A light emitter disclosed in Patent Document 1 includes an insulated substrate formed by a white alumina ceramics substrate, a light-emitting element and a Zener diode loaded on the insulated substrate adjacently to each other, and a resin sealing portion sealing the light-emitting element and the Zener diode. The Zener diode is connected in parallel to the light-emitting element, and prevents flowing of an excess reverse current to the light-emitting element, for example.